From what I've seen, there are two types of bans. Automated bans via Vanguard and manual bans. If your cheat passes the automated checks by Vanguard, then you can cheat for a long time until you amass enough reports to be manually investigated or the cheat's signatures get registered into Vanguard and then get waved.
Valorant is a game played by millions. Thus, they can't perform manual investigations on everyone. So players have to hit a certain report threshold in a certain time period. I.e. receive X reports in Y time period. Honestly, I think the report number is around 100-200.
A lot of cheaters want to drop 30-40 kills every game, and then they have surprised pikachu face when they get banned. If you top frag every game in Dia+ you are getting reported a lot and it's only a matter of time until you hit the manual investigation threshold.
If you have a cheat that doesn't get you auto banned after a couple games AND you legit cheat and never draw too much attention to yourself, then you can last until the next ban wave which can be months.
I think lasting months cheating is reasonable. You should never expect to last years unless you can program your own sophisticated cheat or you pay thousands per month on really private cheats.
Just my 2 cents. But to answer original question, I've used both and had more success with unnamed lately